Bulldoku Level 423: Walkthrough & Solution

Step-by-step Bulldoku level 423 guide (9×9). One pup per color, row and column, no touching. Difficulty 44.4.

Play Level 423

Step-by-step logic

  1. 1. Step: place pup (row 3, column 7)

    After crosses, the mint region has only one legal cell — row 3, column 7. Place a pup there. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 1
  2. 2. Step: place pup (row 2, column 9)

    After crosses, the pink region has only one legal cell — row 2, column 9. Place a pup there. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 2
  3. 3. Step: place pup (row 6, column 1)

    After crosses, the lavender region has only one legal cell — row 6, column 1. Place a pup there. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 3
  4. 4. Step: mark X in column 5

    The orange region is confined to column 5. Mark illegal cells with X.

    Board after step 4
  5. 5. Step: mark X in column 5

    The orange region is confined to column 5. Mark illegal cells with X.

    Board after step 5
  6. 6. Step: place pup (row 7, column 4)

    After crosses, the green region has only one legal cell — row 7, column 4. Place a pup there. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 6
  7. 7. Step: mark X in column 5

    The orange region is confined to column 5. Mark illegal cells with X.

    Board after step 7
  8. 8. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 8
  9. 9. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 9
  10. 10. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 10
  11. 11. Step: mark X (line reservation)

    Several regions share the same rows or columns — other cells on those lines are impossible. Mark them with X.

    Board after step 11
  12. 12. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 12
  13. 13. Step: logical elimination

    Placing a pup on the trial cell would leave a region with no legal move. Mark that cell with X.

    Board after step 13
  14. 14. Step: place pup (row 1, column 3)

    After previous pups, row 1 has only one free cell — column 3. Place the cyan region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 14
  15. 15. Step: place pup (row 9, column 6)

    After previous pups, column 6 has only one free cell — row 9. Place the coral region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 15
  16. 16. Step: place pup (row 4, column 2)

    After previous pups, column 2 has only one free cell — row 4. Place the yellow region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 16
  17. 17. Step: place pup (row 5, column 5)

    After previous pups, column 5 has only one free cell — row 5. Place the orange region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 17
  18. 18. Step: place pup (row 8, column 8)

    After previous pups, row 8 has only one free cell — column 8. Place the blue region's pup here. Mark crosses along the row, column, and neighboring cells (see the board).

    Board after step 18

Final solution

All pups placed correctly: R1 C3, R2 C9, R3 C7, R4 C2, R5 C5, R6 C1, R9 C6, R8 C8, R7 C4

Solved board

Similar difficulty levels

FAQ

How do I solve Bulldoku level 423?
Follow the 18 steps above: find forced placements first, then mark impossible cells with X.
Where can I play level 423 online?
Click "Play Level 423" to open the free browser game with this exact board.